Conveying mechanism



Aug. 13, 1957 P. A. HAUCK CONVEYING MECHANISM 3 Sheets-Sheet 1 FiledDec. 21, 1954 /m m m w m Z Aug. 13, 1957 Filed Dec. 21, 1954 P. A. HAUCKCONVEYING MECHANISM 3 Sheets-Sheet 2 Aug. 13, 1957 P. A. HAUCK 2,802,559

CONVEYING MECHANISM Filed Dec. 21, 1954 I 3 Sheets-Sheet 3 i I 20c l5\ L@ZLNM Z ATTORNEYS Ugimd SW 8 tent 2,802,559 CONVEYING MECHANISM PanlA:Hauck; Union, N. 1.; assignor to Hanson-Van Winkle-Munning Company,Matawan, N. J., a corporation of New Jersey I fnp'pligaao December '21,1954, Serial No. 476,660

7 Claims. (c1. 19s-1a tcernedwith processing machinery of the typedescribed,

which includes novel conveying means for advancing the carriers step bystep from a loading station along the treatment stations to an unloadingstation and for returning. theempty carriers to the loading station. Theprocessing machinery of the invention may be employed for a variety ofpurposes and, since all its advantages are realized in its applicationto electroplating, a machine for such use and embodying the invention,will be illustrated and described in detail.

Automatic electroplating machines commonly include a group ofpreparation tanks for cleaning, etching, and like treatments, one ormore plating tanks, and a group of, tanks for finishing treatments, suchas reclaiming, rinsing, hot rinsing, etc. In conventional machines, aplurality of workpieces are placed upon racks and the loaded racks aremounted upon carriers at a loading station. The carriers are thenadvanced step by step along the machine by conveying means and anelevator operating in the periods of rest of the conveying means raisesand lowers the carriers, so that they can pass over the endof eachtankand be lowered to the following tank. The preparation and finishingtreatments are of relatively short duration, so that theworkpieces arelowered into the tanks and raised therefrom on the next ascent of theelevator. The plating operation takes longer and, accordingly, theplating tanks may be of considerable length and the workpieces loweredinto a plating tank may be plated while being moved along the tankwithin the platingsolution. Other machines operate in a skip-stop cycle,and the plating is carried on at stations in plating tanks, to which thecarriers removed from the last preparation Itank are transferred insequence, until all the stations are filled. Thereafter; the carriersare removed from the stations in the order in which they were deliveredto the stations. In both kinds ofplating operation, the carriers removedfrom the plating tanks are moved along the group of finishing tanks fortreatment therein and, after the last finishing treatment, theloaded-racks are removed from the carriers at an unloading station andthe emptycarriers are returned to the loading station. In electroplatingmachines of either typc,,it is common practice to provide a separateconveyor and elevator for each of the groups of preparation andfinishing tanks and for the plating stations. -In electroplatingmachines, it is desirable that the empty carriersbe returned to theloading station by a single conveyor, which removes the carriers fromthe finishing tank conveyor and delivers themto the preparation-tankconveyor while both the latter conveyors are at rest. It is alsodesirable that the return conveyor be is nearly continuous movement aspossible, so that loading and loading stations may be kept to a .Thelengths of the period of movement and the period of rest in a cycle ofoperation of the preparation and finishing tank conveyors are ordinarilythe same, but the cycles are not in synchronism. Accordingly, it isdifiicult to operate the return conveyor in proper timed relation to thetwo conveyors and have little interruption in the movement of the returnconveyor.

I Thepresen invention is, accordingly, directed to novel conveying meansfor use in processing machinery as described, which advances workpiececarriers step by step along treatment stations by a plurality ofconveyors to an unloading station and returns the empty carriersto aloading station by a single conveyor operating almost continuously. Theconveying means are so constructed that exact timing of the returnconveyor in relation to the conveyors at the loading and unloadingstations is unnecessary and the almost uninterrupted operation of thereturn conveyor makes it possible to run the conveyor at a relativelylow speed and, at the same time, keep the number of empty carriers inreturn transit to a minimum.

For a'better understanding of the invention, reference may be made totheaccompanying drawings, in which Fig. l is a diagrammatic view in sideelevation of an electroplating machine, in which the new conveyingsystemv is employed;

' Fig. 2 is a side elevational view of a portion of the conveying systemnear the loading station;

Fig. 3 is a sideelevational view of a portion of the machine near theunloading station; Fig. 4 is a sectional view on the line 4-4 of Fig. 3;and l v i .Fig. 5 is a time chart.

The machinesillustrated includes preparation or preplating tanks10,.plating tanks 11, and finishing or postplating tanks 12 and theworkpieces W are carried along the tanks on racks 13, which are nrountedon carriers 14 at a loading station in front of the first of thepreplating tanks. Each carrier comprises an axle 15 having flangedwheels 16 at its ends and a sleeve 17 encircles the axle and is providedwith a pair of hooks 18, in which the top bar 13a of a rack may beinserted. The wheels of the carriers roll on tracks lying on oppositesides of the tanks and formed by angle irons 19 attached to beams 19a ofelevator structures 20a, 20b, 20c, extending along the pro-plating, theplating, and the postplating tanks, respectively. The elevatorstructures are of conventional construction and they are verticallymovable in guideways on the framework 21 of the machine by the usualmechanism.

The carriers are advanced along the tracks over. the pre-plating tanksby a conveyor 22 and conveyors 23 and 24 advance the carriers along thetracks over the plating and post-plating tanks, respectively. Theconveyors are of the same construction and the details of conveyor 24are illustrated in Figs. 3 and 4. The conveyor is formed of a pair ofendless chains 25 lying in vertical planes in upper and lower horizontalstretches. Each chain is provided with rollers 26 and the rollers in thehorizontal stretches of the chains run on guides 27. The means on thechains .for engaging and advancing the carriers are yokes 28 formed ofplates, which are attached to links of the chains and have recesses 28afor receiving the axle 15 of a carrier. Each chain is trained aboutnotched wheels 29 on shaft 30 and one of the shafts is driven by a motor31 connected to the shaft through a speed reducer 32 and a drive chain33.

umber of'idlejcarriers in transit between the unanismldisclosedin. my"co-pending application, ;Serial No,

443,193; filed July 14, 1954, may be used for the purpose, if desired.'Each'loaded carrier is thenrmoved along the tracks of the elevator 20aover the pre-plating tanks 10 by conveyor 22 and broughtto rest abovethe tanks .succe'ssively; In each period of rest, the elevator movesdown to immerse workpieces on carriers on theelevator in the tanks andthen rises. When a loaded-carrier reaches the last pre-plating tank"10a, it is transferred to the tracks of the elevator 20b extending overthe plating tanks. Adjacent the ends of the tracks, the two elevatorslie close together and the tracks of elevator 29!; extend over tank 10a.The transfer of a carrier from the tracks of elevator 20a to those ofelevator 20b may then be effected by suitable mechanism, such as a'hydran'liccylinder 34 mounted on tank 10a in such position that itspiston 34a can be operated to move a carrier along the top'of the tankfrom the place Where it has deposited by elevator 20a to a position, inwhich it will be picked up by elevator 20b.

The loadedcarriers removed from the last pre-p'lating tank 10a areadvanced along the tracks of elevator 2012 by conveyor 23 and aredeposited in the plating tanks in accordance with a skip-stop cycle.When the plating of the workpieces on a carrier has been completed, thecarrier is picked up by elevator 20b on the .next' ascent of thatelevator and the carrier is then advanced along the rails of conveyor20b to the end of the rails. 20b partially overlies the firstpost-plating tank 12a. and its rails terminate close to those ofelevator 20c. When a carrier has been deposited in tank 12a byelevator2072-, it is moved along the tank to a position, in which it can bepicked up by elevator 20c, and the mechanism for this purpose may be ahydraulic cylinder 35 functioning in the same manner as cylinder 34.

When a carrier has been advanced along all thepostplating tanks, itcomes to rest at an unloading station adjacent the end of the rails onconveyor 20c and the loaded rack with the finished workpiece is removedfrom' the carrier by suitable means, such as the transfer mechanismdisclosed in my co-pending application, a'bove identified. The emptycarrier is'then moved up to the upper horizontal'stretch ofthe chains ofconveyor 24 and, in such movement, the carrier is guided by curvedguides 36, which retain it in its yokes 28 on conveyor 24. .The emptycarriers are returned from conveyor .24 to conveyor 22 by a returnconveyor 37, which is of the same construction as the other conveyorsand includes chains 38 having upper and lower stretches and rollers 39on the chains, which run on tracks 40 beneath the horizontal stretches.The chains are provided, with aligned pairs of pusher elements 41, 42(Fig. 2'), and the plates of each pair are spaced to receive the axle 17of a carrier between them. The pusher elements in the upper horizontalstretch of conveyor 37 return the empty carriers and, during the returnmoveinentof the carriers, their rollers run on tracks formed by beams 43mounted on the framework of the machine. 7 The return conveyor 37intersects the upper stretches of conveyors 22 and 24 near the ends ofthose stretches. The intersections of conveyor 37 with conveyor 24occurs at aligned points 44, at which yokes 28 on conveyor 24 come torest during the stepwise movement of the conveyor. Adjacent points .44,the chains 38 of conveyor 37 pass around notched wheels 45 and thewheels are so disposed that, as aligned pairs of pusher elements 41, 42.on chains 38 move by the points, the elements 42 pass at one side ofthe axle of a carrier in yokes 28. at points 44, while the elements 41engage the axle to advance the carrier. Upper and lower curved guides 46lead from points 44 to insure that the carrier removed from yokes willbe properly engaged and advanced by conveyor 37.'

The chains 38 of conveyor 37 are led'about notched wheels 47 close tothe place where conveyor 37 intersects conveyor 22, and adjacent thenotched wheels, upper and lower'guides 48 are mounted in such relationto con- Conveyor v 4 veyor 37 that the axle of a carrier being moved bypusher elements 41, 42 will enter the guides and thus leave the conveyorto travel through the guides by gravity. The conveyor 22 is soconstructed thatv apair of yokes 28 thereon come to rest at points 49just beyond the wheels 47 and the guides 48 lead to those yokes. As the,carriers are of substantial weight, a resilient bumper 50 is disposed atpoints 49 in such position as to cushion the carriers as they enter apair of yokes. Beyond points 49, upper and lower tracks 51 guidecarriers being advanced in yokes 28 on conveyor 22 and direct suchcarriers tothe tracks of elevator 20a.

The time chart forming .Fig. 5 discloses one. cycle of operation of theconveyors 22,24, and 37'and parts of the preceding and succeedingcycles. The conveyors 22 and 24 each operate in a cycle, in which thereis a single movement and a period of rest of substantially greaterduration than the length of the period of movement. The movement ofconveyor 22 terminatesbe'fore the'movement of conveyor 24 starts and,when conveyor 24'stops, both conveyors 22 and 24 remain at rest'for'aconsiderable period. The conveyor 37 operates in a cycle, which'includesa long period of movement and a'short period of rest. The movementof-conveyor 37 preferably starts simultaneously with the :stopping ofconveyor '24'and continues, throughout the common period of rest of'conveyors 22 and 24 and to a time during'the next period of movement ofconveyor 24.

vA cycle of the conveying system made up of the three conveyors may beconsidered to start 'atthe time A. Atithis instant, conveyor 24 has justcome to rest with an empty carrier supported in yokes at points 44. Asconveyor 24 stops, conveyor 37 may be started in any desired manner, as,for example, by means of a limit switch LSr'mounted near points 44 andhaving an operating arm actuated by a carrier as it approaches points44. With the stopping of conveyor 24, that conveyor and conveyor 22 havea period .of rest in common and, during this period, aligned pairs ofpusher elements 41, 42 on conveyor '37 engage and remove an emptycarrier from conveyor 24 at points 44 and other pusher elements adeliver an empty carrier to the yokes on conveyor 22 at points 49. Inorder that there may be an ample margin of safety in the timing of theconveyors, the conveyor 37 has been stopped with aligned pairs of.pusher elements thereon at points 5.2 and 53, which are in front of andspaced from points 49 and 44, respectively. The stopping ofconveyor .37as described may be effected by means of a limit switch LS2 having anoperating arm, which is engaged by a carrier as it reaches points 52.When conveyor 37 is startedfit runs for a period represented by thedistance between times A and B, before the pusher, elements travel. frompoints 52 to points 49 and from points 53 to points 44. As the elementsreach the respective points, one set dis charges an empty carrier, whichis guided into a pair of yokes on conveyor 22, while the other setremoves an empty carrier from yokes of conveyor 24 and starts itsreturn. As the discharge and removal of the carriers occurs well afterconveyor 37 has started and within the common period of rest ofconveyors 22 and 24', exact timing of the conveyor movements is notrequired. When conveyor 37 has delivered a carrier to conveyor 22 andremoved a carrier from conveyor 24, conveyors 22 and 24 may be operatedand, during their movement, conveyor 37 may continue in operation, untilit is stopped .by limit switch LS2. The time, at which conveyor .37stops, is represented by point C on the time chart and it occurs duringa'period of movement of conveyor 24. It will be noted that the time ineach cycle of the conveying system, during which conveyor 37 is moving,is much longer than the periods of movement of 'conveyors22and 24.Accordingly, conveyor 37 may'move at a relatively low speed and stillreturn carriers from conveyor 24 tofconveyor 22 with only a fewcarriers'in transit at any time.

' The machine shown comprises three conveyors 22, .23,

and 24 between the loading and unloading stations but, since only thefirst conveyor 22 and the last conveyor 24 cooperate with the returnconveyor 37, the intermediate conveyor 23 may be omitted, if desired, orit may be replaced by as many other conveyors as are needed.

I claim:

1. A processing machine, which comprises a plurality of workpiececarriers, first and second conveyors disposed in alignment and operatingintermittently with a period of rest in common between successivemovements, spaced attachments on the conveyors for releasably engagingand advancing the carriers, means for transferring the carriers from thefirst conveyor to the second, a third conveyor intersecting the paths ofthe first and second conveyors near points, at which attachments thereoncome to rest in the intermittent movement of the first and secondconveyors, spaced attachments on the third conveyor operating to removecarriers from the second conveyor at the point of intersection of thethird conveyor with the path of the second conveyor for transport by thethird conveyor and to discharge the transported carriers near the pointof intersection of the third conveyor with the path of the firstconveyor, means for receiving each discharged carrier and delivering itto an attachment on the first conveyor, means for stopping the thirdconveyor with a pair of attachments thereon adjacent to and in front ofsaid points of intersection, respectively, and means for starting thethird conveyor in time to cause said pair of attachments to pass saidpoints of intersection, while the first and second conveyors arestopped.

2. The machine of claim 1, in which the means for stopping the thirdconveyor is actuated by an element moving with that conveyor.

3. The machine of claim 1, in which the means for starting the thirdconveyor is actuated by an element moving with the second conveyor.

4. The machine of claim 3, in which the means for starting the thirdconveyor is actuated simultaneously with the stopping of the secondconveyor.

5. The machine of claim 2, in which each movement of the second conveyorterminates after the end of the corresponding movement of the firstconveyor and the third conveyor is stopped by its stopping means duringthe movement of the second conveyor.

6. The machine of claim 1, in which the means for receiving eachdischarged carrier includes guide means, along which the carrier movesby gravity, and cushioning means for arresting the movement of thecarrier.

7. The machine of claim 1, in which each of the conveyors includes atleast one endless chain having an upper and a lower horizontal stretch,the third conveyor intersects the paths of the first and secondconveyors near points, at which attachments on the upper stretches ofthe first and second conveyors come to rest in the intermittent movementof the first and second conveyors, and attachments on the upper stretchof the third conveyor advance carriers with that conveyor from the pointof intersection of the third conveyor with the path of the secondconveyor to approximately the pointof intersection of the third conveyorwith the path of the first conveyor.

References Cited in the file of this patent UNITED STATES PATENTS1,837,605 Baker Dec. 22, 1931

